The present invention relates to a method and an apparatus for the individual marking of green sand molds.
To reduce the number of reject parts during casting due to pattern plate wear, defective shims or cores and incorrect inoculation, it is known to apply identification marks or tags to the pattern plates. The core marks or tags contain the following information: production year, production month, production day, hour and quarter of an hour. Until now, these identification marks/tags have been altered manually at approximately quarter-hourly intervals.
A disadvantage of the known methods is the loss in cycle time which occurs four times every hour when altering the marks. In addition, the additional set-up times necessary when changing a pattern for applying or removing the marks/tags, which involves relatively high costs in pattern making, must be taken into consideration.
In addition, the vertical integration of production in most product sectors is nowadays considerably less than in past years and in the automobile industry is currently about 35%. This means that about 65% of automotive parts are produced by outside companies or subcontractors. The products from the subcontractors therefore have to be unequivocally marked, in order that
1. the supplier can be established as the producer of the product, PA1 2. the product can be identified and PA1 3. the product marking can be verified.
The markings must be applied in a way appropriate for the material, that is they must not impair the function of the parts and should be indelible so that they do not become illegible by the normal use or operation of the castings.
A marking appropriate for a purpose or material initially only has the effect of causing costs, both on the design side and on the production side, so that the use of a cost-effective method is of major importance.
It is the principle object of the present invention to provide a method for marking sand molds which can be used cost-effectively for high-speed molding plants. The method of the present invention saves cycle time losses and pattern making costs. In addition, it is possible to integrate the method into existing molding plants without any great expenditure of time and money.